|School of Plant, Environmental and Soil Sciences|
|224 M. B. Sturgis
Baton Rouge, LA 70803
B.A. in Chemistry, Louisiana State University, 1977
M.S. in Agronomy, Louisiana State University, 1982
Ph.D. in Soil Science, University of Florida, 1987
I have tried to find practical and simple order in soils and environmental effects of how they are managed. Some results serve to illustrate. The mobility of major cations in soils can be predicted based on sorption-desorption with reference substances, a potentially widely useful finding with ramifications. The loss of nutrient cations from forest soils due to acid deposition depends on the anionic composition of the pollutant –greater sorption by sulfate than nitrate, less loss, simple. Despite spatial and temporal variability in a soil type, the fate of several dissimilar pesticides can be anticipated surprisingly well from simple tests. Although predicting phosphorus loss in runoff from soils is evidently not a simple matter, loss can be mimicked using a simple apparatus, a practical finding. Plant uptake of soil phosphorus is a workable solution to the problem but it takes a while. More uniform distribution of nutrients in a grazed pasture is a matter of moving the watering trough from place to place.
I teach (introductory) Soil Science (AGRO / EMS 2051) 2 semesters each year, Advanced Soil Chemistry (AGRO 7055) once every other year and Special Topics in Soil Science (AGRO 4092) as needed. I have received the Gamma Sigma Delta Teaching Merit Award several times.
While farmers have always tried to preserve and improve the resource base of their livelihood, the soil, in recent times we have come to recognize that farming practices may affect the broader environment for better or worse. My research as a soil chemist has examined the effects of soil management (including tillage, animal waste fertilizer, cattle grazing and type of crop grown) and soil spatial variability on soil and water quality, and the fate of nutrients and pesticides, with the objective of determining how current practices may be practically adjusted to improve environmental quality or minimize potentially negative effects. To varying degrees, my work has involved all of the major agronomic crops of Louisiana. However, I have most recently devoted the majority of my agricultural research effort to possible environmental problems and economic possibilities in the hilly, coastal plain part of the State. Beside forestry, poultry-cattle-hay production is the main agricultural enterprise of this region, and its future will doubtlessly be affected by how successfully it deals with poultry waste and phosphorus-enriched soils. Though the landscape is unsuitable for higher-value row crops, it could support biomass grass production and, in fact, may be ideal for this use. Provided a robust market for these raw materials develops, this region of the State might have a resurgence in its agricultural economy. However, this also depends on the sustainability of biomass grass production and environmental quality. There is a reasonable possibility that poultry and biomass production could mutually benefit one another, and my research includes use of poultry litter fertilizer with biomass grasses as well as remedies for soils overly-enriched with phosphorus from it.
Blazier, M.A., H.O. Liechty, L.A. Gaston and K. Ellum. 2011. Poultry litter fertilization impacts on soil, plant, and water nutrient cycling in loblolly pine (Pinus taeda L.) plantations and silvopastures in the mid-South USA. In: Principles, Application and Assessment in Soil Science, InTech http://www.intechopen.com/books/principles-application-and-assessment-in-soil-science/poultry-litter-fertilization-impacts-on-soil-plant-and-water-characteristics-in-loblolly-pine-pinus
Locke, M.A., D.D. Tyler and L.A. Gaston. 2010. Soil and water conservation in the mid-south United States: Lessons learned and a look to the future. p. 201-236. In T.M. Zobeck and W.F. Schillinger (ed.) Soil and Water Conservation Advances in the United States. ASA, Madison, WI.
Locke, M.A., R.M. Zablotowicz, and L.A. Gaston. 2003. Environmental fate of fluometuron in a Mississippi Delta lake watershed. In E.L. Arthur, C.E. Clay, and A. Barefoot (eds.) Terrestrial field dissipation studies: Purpose, design, and interpretation. ACS Symposium Series. ACS Symposium Series 842. American Chemical Society, Washington, DC.
Selim, H.M., R.S. Mansell, L.A. Gaston, H. Fhühler and R. Schulin. 1993. Prediction of cation transport in soils using cation exchange reactions. In K. Roth, H. Fhühler, W.A. Jury and J.C. Parker (eds.) Field-Scale Water and Solute Flux in Soils, Birkhäuser Verlag, Basel.
Gaston, L.A., R.S. Mansell and H.M. Selim. 1992. Predicting effects of influent acidity upon ion transport in acid sandy soil. In I.K. Iskandar and H.M. Selim (eds.) Engineering Aspects of Metal-Waste Management, Lewis Publishers, Boca Raton, Fla.
Gaston, L.A., R.S. Mansell, R.D. Rhue, S.A. Bloom and B.G. Volk. 1987. Cation leaching during application of sulfuric and nitric acids to an Ultisol. p. 421-428. In R. Perry (ed.) Acid Rain: Scientific and Technical Advances, Selper, Ltd., London.
Burwell, R.W., J.S. Beasley, L.A. Gaston, S.M. Borst, R.E. Sheffield, R.E. Strahan, and G.C. Munshaw. 2011. Losses of surface runoff, total solids, and nitrogen during bermudagrass establishment of levee embankments. J. Environ. Qual. 40:1241-12.48.
Udeigwe, T.K., J.J. Wang, H.P. Viator and L Gaston. 2010. Surface water quality as affected by sugarcane residue management techniques. Water, Air Soil Pollut. 208:119-128.
Dubeux, J.C.B., L.E. Sollenberger, L.A. Gaston, J.M.B. Verdramini, S.M. Interrante and R.L. Stewart, Jr. 2009. Animal behavior and soil nutrient redistribution in continuously stocked Pensacola bahaigrass pastures managed at different intensities. Crop Sci. 49:1503-1510.
Liechty, H.O., J.D. Richardson, R.L. Fickin, L.A. Gaston, M.A. Blazier and J.P. Wight. 2009. Assessment of repeated application of poultry litter on phosphorus and nitrogen dynamics in loblolly pine: Implications for water quality. Forest Ecol. Management. 258:2294-2302.
Viator, H.P., B. Legendre, C. Kennedy, M. Zhou, J.J. Wang, T. Hymel, L. Gaston, J. Hoy and S. Hall. 2009. The influence of post-harvest residue management on water quality and sugarcane yield in Louisiana. J. Amer. Soc. Sugar Cane Technologists. 29:1-10.
Yuan, Y., M.A. Locke and L.A. Gaston. 2009. Tillage effects on soil properties and spatial variability in two Mississippi Delta watersheds. Soil Sci. 174:385-394.
Blazier, M.A., L.A. Gaston, T.R. Clason, K.W. Farrish, B.P. Oswald and H.A. Evans. 2008. Nutrient dynamics and tree growth of silvopastoral systems: Impact of poultry litter. J. Environ. Qual. 37:1546-1558.
Powell, S, S. Johnson, L. Gaston and L.L. Southern. 2008. The effect of dietary phosphorus level and phytase supplementation on growth, performance, bone-breaking strength, and litter phosphorus concentration in broilers. Poult. Sci. 87:949-957.
Gaston, L., M.Locke, J. McDonald, S. Dodla, L. Liao, L Putnam and T. Udeigwe. 2007. Effects of tillage on norflurazon sorption, degradation and mobility in a Mississippi Delta soil. Soil Sci. 172:534-545.
Zablotowicz, R.M., M.A. Locke and L.A. Gaston. 2007. Tillage and cover crop effects on soil microbial properties and fluometuron degradation. Biol. Fertil. Soils. 44:27-35.
McDonald, J.A., L.A. Gaston, S.H. Jackson, M.A. Locke, and R.M. Zablotowicz. 2006. Degradation kinetics assessment for the fungicide BAS 505 in intact soil cores versus batch soils. Soil Sci. 171:1-10.
Locke, M.A., R.W. Steinriede, L.A. Gaston, R.M. Zablotowicz and P.J. Bauer. 2005. Conservation cotton production in the southeastern United States: Herbicide dissipation in soil and cover crops. Weed Sci. 53:717-727.
Shelton, J.L., L.L. Southern, L.A. Gaston, and A. Foster. 2004. Evaluation of the nutrient matrix values for phytase broilers. J. Appl. Poult. Res. 13:213-231.
Gaston, L.A., D.J. Boquet, and M.A. Bosch. 2003. Fluometuron sorption and degradation in cores of silt loam soil from different tillage and cover crop systems. Soil Sci. Soc. Am. J. 67:747-755.
Gaston, L.A., D.J. Boquet, and M.A. Bosch. 2003. Pendimethalin wash-off from cover crop residues and degradation in a loessial soil. Commun. Plant Soil Analysis. 34:2515-2527.
Gaston, L.A., C.M. Drapcho, S. Tapadar, and J.L. Kovar. 2003. Phosphorus runoff relationships for Louisiana coastal plain soils amended with poultry litter. J. Environ. Qual. 32:1422-1429.
Gaston, L.A., T.L. Eilers, J.L. Kovar, D. Cooper, and D.L. Robinson. 2003. Greenhouse and field studies on hay harvest to remediate high phosphorus soil. Comm. Soil Sci. Plant Anal. 34:2085-2097.
Gaston, L.A., and M.A. Locke. 2002. Differences in microbial biomass, organic carbon and dye sorption between flow and no-flow regions of unsaturated Dundee soil. J. Environ. Qual. 31:1406-1408.
Locke, M.A., K.N. Reddy, L.A. Gaston, and R.M. Zablotowicz. 2002. Adjuvant modification of herbicide interactions in aqueous soil suspensions. Soil Sci. 167:444-452.
Gaston, L.A., D.J. Boquet, and M.A. Bosch. 2001. Fluometuron wash-off from cover crop residues and fate in a loessial soil. Soil Sci. 166:681-690.
Gaston, L.A., and M.A. Locke. 2001. Comparison of methodologies for extraction of acifluorfen from soil. Comm. Soil Sci. Plant Anal. 32:2953-2964.
Gaston, L.A., M.A. Locke, R.M. Zablotowicz, and K.N. Reddy. 2001. Spatial variability of soil properties and weed populations in the Mississippi Delta. Soil Sci. Am. J. 65:449-459.
Gaston, L.A., and M.A. Locke. 2000. Acifluorfen sorption, degradation and mobility in a Mississippi Delta soil. Soil Sci. Soc. Am. J. 64:112-121.
Zablotowicz, R.M. M.A. Locke, L.A. Gaston and C.T. Bryson. 2000. Interactions of tillage and soil depth on fluometuron degradation in a Dundee silt loam soil. Tillage Res. 57:61-68.
Locke, M.A., L.A. Gaston and R.M. Zablotowicz. 1997. Acifluorfen sorption and sorption kinetics in soil. J. Agric. Food Chem. 45;286-293.
Reddy, K.N., M.A. Locke and L.A. Gaston. 1997. Tillage and cover crop effects on cyanazine adsorption and desorption kinetics. Soil Sci. 162:501-509.
Gaston, L.A., M.A. Locke and R.M. Zablotowicz. 1996. Sorption and degradation of bentazon in conventional- and no-till Dundee soil. J. Environ. Qual. 25:120-126.
Gaston, L.A., and M.A. Locke. 1996. Bentazon mobility through intact columns of conventional- and no-till Dundee soil. J. Environ. Qual. 25:1350-1356.
Gaston, L.A., M.A. Locke, S.C. Wagner, R.M. Zablotowicz and K.N. Reddy. 1996. Sorption of bentazon and degradation products in two Mississippi soil. Weed Sci. 44:678-682.
Locke, M.A., L.A. Gaston and R.M. Zablotowicz. 1996. Alachlor biotransformation and sorption in soil from two soybean tillage systems. J. Agric. Food Chem. 44:1128-1134.
Wagner, S.C., R.M. Zablotowicz, L.A. Gaston, M.A. Locke and J. Kinsella. 1996. Bentazon degradation in soil: Influence of tillage and history of bentazon application. J. Agric. Food Chem. 44:1593-1598.
Gaston, L.A., and M.A. Locke. 1995. Fluometuron sorption and transport in Dundee soil. J. Environ. Qual. 24:29-36.
Reddy, K.N., M.A. Locke, S.C. Wagner, R.M. Zablotowicz, L.A. Gaston and R.J. Smeda. 1995. Chlorimuron ethyl sorption and desorption kinetics in soils and herbicide-desiccated cover crop residues. J. Agric. Food Chem. 43:2752-2757.
Gaston, L.A., and M.A. Locke. 1994. Predicting alachlor mobility using batch sorption kinetic data. Soil Sci. 158:345-354.
Hinz. C., L.A. Gaston and H.M. Selim. 1994. Effect of sorption isotherm type on prediction of solute mobility in soil. Water Resour. Res. 30:3013-3021.
Locke, M.A., S.S. Harper and L.A. Gaston. 1994. Metribuzin mobility and degradation in undisturbed soil columns. Soil Sci. 157:279-288.
Mathews, B.W., L.E. Sollenberger, P. Nkedi-Kizza, L.A. Gaston and H.D. Hornsby. 1994. Soil sampling procedures for monitoring potassium distribution in grazed pastures. Agron. J. 86-121-126.
Nkedi-Kizza, P., L.A. Gaston and H.M. Selim. 1994. Extrinsic spatial variability of selected macronutrients in a sandy soil. Geoderma 63:05-106.
Gaston, L.A., H.M. Selim and P.M. Walthall. 1993. Predicting cation transport in smectitic soils. Soil Sci. Soc. Am. J. 57:307-310.
Selim, H.M., L.A. Gaston and R.S. Mansell. 1993. Predicting the mobility of exchangeable ions in soil. p. 141-146. Proceedings of the International Conference Physical Chemistry and Mass-Exchange Processes in Soils, Pushchino, Russia, October 12-16, 1992.
Gaston, L.A., R.S. Mansell and H.M. Selim. 1992. Predicting removal of major soil cations and anions during acid infiltration: Model evaluations. Soil Sci. Soc. Am. J. 56:944-950.
Gaston, L.A., and H.M. Selim. 1991. Predicting cation mobility in kaolinitic media based on exchange selectivities of kaolinite. Soil Sci. Soc. Am. J. 55:1255-1261.
Gaston, L., P. Nkedi-Kizza, G. Sawka and P.S.C. Rao. 1990. Spatial variability of morphological properties at a Florida flatwoods site. Soil Sci. Soc. Am. J. 54:527-533.
Gaston, L.A., and H.M. Selim. 1990. Transport of exchangeable cations in an aggregated clay soil. Soil Sci. Soc. Am. J. 54:31-38.
Gaston, L.A., and H.M. Selim. 1990. Predicting cation mobility in montmorillonitic media based on exchange selectivities of montmorillonite. Soil Sci. Soc. Am. J. 54:1525-1530.
Gaston, L.A., R.S. Mansell and R.D. Rhue. 1986. Sulfate mobility in acid soils and implications with respect to cation leaching: A review. Soil Crop Sci. Soc. Fla. 45:67-72.
L. Gaston, J.J. Wang, and C. Jeong. 2013. Soil quality for environmental resilience. Louisiana Agriculture. 56(2):38.
Wang, J.J., and L. Gaston. 2011. Land-applied animal waste and water quality. Louisiana Agriculture. 54(4):16-17.
Gaston, L., D. Cooper and M. Stephens. 2010. Using hay harvest to reduce elevated soil phosphorus. Louisiana Agriculture. 53(2):27:29.
Powell, S., L. Johnson, T. Lavergne, T. Bidner, L. Southern and L. Gaston. 2010. Effect of dietary phosphorus level and phytase supplementation on growth performance, bone strength and phosphorus excretion in broilers. Louisiana Agriculture. 53(2):26-27.
Viator, H.P., R. Bengston, S. Hall, L. Gaston, M. Selim, J. Wang, B. Legendre, T. Hymel, J. Flanagan, J. Hoy, C. Kennedy and J. Prudente. 2008. Influence of sugarcane post-harvest residue management on yield,, water quality. Louisiana Agriculture. 51(2):39-40.
Gaston, L.A., and P.K. Bollich. 2004. Meeting Standards for Rice and Soybeans. Louisiana Agriculture. Vol. 47(2):10.
Shelton, J.L., L. Johnston, S.B. Williams, R. Payne, L.L. Southern, T. Bidner and L. Gaston. 2004. Adding phytase proves positive for poultry, swine diets. Louisiana Agriculture. Vol. 47(4):12-13.
Gaston, L.A. 2003. Tillage and cover crop effects on herbicide degradation. Louisiana Agriculture. Vol. 46(2):29.
Gaston, L., T. Clason and D. Cooper. 2003. Benefits of poultry litter fertilizer on pasture, silvopasture and forest soils. Louisiana Agriculture. Vol. 45(3):22-23.
Gaston, L.A., M.A. Locke, R.M. Zablotowicz, and K.N. Reddy. 2001. Spatial relationships among soil properties and weed populations in Beasley Lake watershed. In R.A. Rebich and S.S. Knight (eds.) The Mississippi Delta Management Systems Evaluation Areas Project, 1995-1999. Mississippi Agricultural and Forestry Experiment Station Information Bulletin 377.
Gaston, L.A., D.J. Boquet, S.D. Dotch, and M.A. Bosch. 2001. Cotoran wash-off from cover crop residues and degradation in Gigger soil. p. 144-154. In P.K. Bollich (ed.) Proceedings of the 23rd Annual Southern Conservation Tillage Conference for Sustainable Agriculture. Monroe, LA. June 19-21.Locke, M.A., R.M. Zablotowicz and L.A. Gaston. 1995. Fluometuron interactions in crop residue-managed soils. In W.L. Kingery and N. Buehring (eds.) Proceedings of the 1995 Annual Southern Conservation Tillage Conference for Sustainable Agriculture. Jackson, MS, June 26-28.